The first thing I did straight out the box was remove the roll cage for access and thread locked all necessary screws. The 2 screws for the engine cover mounting on the bottom were I'd say only finger tight so it's defo worth checking everything.
Before attempting fitting the kill switch I ran the engine and all was well even the throttle servo at this point. After this I found that the positive coil terminal was broken after fitting the kill switch, the reason for no spark.
Spare servo and carb borrowed from another model and everything seems good now (can't give it a proper run till Sunday)
The standard car off the KM was a walbro 668. I remember last year I bought one of these from Freeprawn racing which was faulty but slightly different symptoms, they replaced it, after that was spot on.